Preheat the oven to 375 °F. Line an 8 or 9-inch square baking pan with parchment paper and grease lightly with cooking spray, set aside.

For the crust, place the butter, granulated sugar, and vanilla in a large bowl and beat until light and fluffy. about 2 minutes. Add the flour, 3/4 teaspoon salt and 1/2 teaspoon cinnamon beat until combined. Scatter two-thirds of the dough in clumps in the prepared pan and press it lightly with floured hands on the bottom. Refrigerate for 20 minutes. Bake for 18 to 20 minutes, until the crust is golden brown; set aside to cool.

For the filling, in a large bowl, combine the chocolate, remaining 1/4 teaspoon salt and 1/4 teaspoon cinnamon. Heat the cream until barely simmering and then pour over the chocolate and let stand for 5 minutes before stirring until melted through and glossy. Pour the ganache over the cooled crust and spread it out into an even layer.

Reduce oven to 350°F. Stir the walnuts into the remaining dough and mix until crumbly. Sprinkle evenly over the top of the ganache. You don't have to cover it completely. Bake until golden brown and the ganache has set, and just barely jiggles when you shake the pan lightly, about 15 to 20 minutes. Remove from the oven and let cool completely to room temperature. Chill for at least 30 minutes before removing from the pan and slicing into 16 squares. Enjoy!